This article is written from the perspective of a person who struggled with chronic pain and RSI symptoms for years, exhausted the traditional medical system, and was willing to basically try anything. I am not a doctor, and this is not medical advice.  You should definitely try the regular medical system first or in combination with the things on this page.  This is a list of things to look into;  some can help quickly and others take months or years of consistent work.  

But before I get to those things, I need to talk about what my general theory about chronic pain and RSI has evolved to be.

The traditional medical system has no idea what the cause of chronic pain is. There are a bunch of theories floating around, but doctors are mostly clueless and are throwing darts with a blindfold on. Sometimes, you can get diagnosed with a more specific chronic pain condition, like RSI (Repetitive Stress Injury) or Tendonitis or Tendinosis. 

If you read the first page of Google results, they all sound like they were written by the same person and they all go like this: Too much repetitive motion leads to micro-injuries in your tendons. Your body's reaction is inflammation, which causes swelling and pain, and if you ignore the swelling and pain the condition leads to a chronic degenerative condition in which your body's ability to heal is overwhelmed and instead of replacing the micro injuries with healthy collagen, it replaces them with unhealthy collagen. As more and more unhealthy collagen is deposited in your tendons, they become weaker, and more susceptible to injury and there is a downward spiral.

Note that this is a completely physical explanation, because that's how the traditional medical system works.

Now, if you've done any research at all, you will probably have run across a mention of Dr. Sarno. At the risk of greatly oversimplifying, his theory is that the problem is not physical at all but instead "all in your head". If you read his book and follow his instructions, you basically attempt to convince yourself that you're not actually sick, and in that process will stop showing symptoms of being sick.

I have no doubt that this works for some people, and it is absolutely worth trying. There are anecdotal reports of this working quite quickly for some, and I am interested in nothing except what works. However, I did read his book, it did not work for me at all, and my personal theory is that his theory is incomplete.

I do not believe that the problem is purely physical, nor do I believe the problem is purely "in your head". There is a "Mind-Body" connection, and if Dr. Sarno's easy/quick solution doesn't work, there is a longer and more holistic way of approaching the problem with eventually worked for me.

My theory is that the problem is complex, and caused partially by a lot of different factors: stress, lifestyle, nutrition, chronic tension, bad posture, etc. However, it is also "in your head" in a very general sense, and if you can convince your subconscious that you are making changes in your life to address the problem, your symptoms will improve in a way that is very similar to the placebo effect.

So, to reiterate, my theory is that you need to make broad changes in many parts of your life that will help and also convince you that you are helping,  which will itself help things.

Below, I've listed everything that I've discovered that might help. Some things are quick and easy, and some things take months or years to really see the results.

Stress and environment

I believe that the vast majority of chronic pain is real (not "imaginary/in your head"), but also caused by stress and tension.

What most people do not realize is that they walk around in a state of chronic tension. Just take a moment and focus on, say, the muscles in your shoulders and consciously relax them. Watch what happens. Your shoulders are probably chronically tense, and you may be surprised to notice that almost every muscle in your body is chronically tense. I once had a massage therapist tell me that the muscles in my arms felt like guitar strings.

A stressful environment only makes this worse, and it becomes a self reinforcing cycle: First you get stressed, then you have pain, the pain makes you concerned and more stressed, you try to dream up ways to work around the pain which makes you stressed, the stress makes you more tense, etc, etc.

There are two ways out of this: You can reduce the stress directly, or you can work on your body awareness so that you can be aware of the tension. Once you are aware of the tension you can consciously relax it.

Reducing the stress directly means changing your environment. That can be with nutrition, exercise, switching to a less stressful job, using better tools, being in nature,

Becoming aware of the tension is a much longer process and can be done using techniques like Reichian breathwork (every teacher has a different style), Yoga (esp. Hatha or Vinyasa), or mindfulness meditation (Reggie Ray is excellent for this).

Better tools

The first thing that comes to mind for most people when faced with chronic pain in a work environment is to try to get some better tools. This is absolutely worth doing.

Not only will better ergonomics help directly, but it will help indirectly by convincing your subconscious that it's helping. When your subconscious is convinced that it's helping, it will relax the anticipatory tension, which just relaxes you in general.

Of course, I can only speak to ergonomic tools that are relevant to programmers and others who work on computers.

• Dragon NaturallySpeaking - This is hands down the most valuable thing that helped me through my almost decade of chronic pain. Not having to type everything out is a godsend.
• Kinesis ergonomic keyboards - If you are willing to spend a couple of weeks retraining your brain, these crazy looking keyboards are wonderful for hand and forearm tension.
• Wacom tablets - If you have a particularly hard time with mice, the Wacom tablets work with a pen, and the mouse click is thumb-activated.
• Vertical mice - A great mouse alternative if you don't want to go all the way to a tablet. The vertical orientation reduces tension in your forearm.

Nutrition and Supplements

Note: a lot of my links are Dr Berg.  He's awesome.  But all of this info is available from other sources.

• Vitamin C (only natural sources recommended)- Important for collagen/tendon repair. If you don't have enough vitamin C, your tendons will be more likely to repair using the wrong type of collagen.
• Jell-o or Hydrolized Collagen - It's a major component of connective tissue.
• Copper - Another pro tendon repair element.
• Magnesium (chelated...not Magnesium Citrate because that's a laxative) - Anti stress and aids muscle relaxing.
• Vitamin B1 (from nutritional yeast if possible) - Major anti-stress and anti-anxiety vitamin.  It's depleted when you have a high carb diet.
• Fish Oil/Cod Liver Oil (worth paying extra for good quality) - Anti-inflammatory, anti-depression.
• Tumeric - Anti-inflammatory.
• Anti inflammatory diet - Stay away from seed oils (soybean, corn, rapeseed, cottonseed, sunflower, safflower). They are packed with omega-6 fats, in the modern diet is way out of balance with omega-6.  Omega-6 is inflammatory, omega-3 is anti-inflammatory. Try to get back in balance with olive oil, avocado oil, chia seeds, fish oil or codliver oil.
• Lemon balm tea - Very powerful and safe short term anti-stress supplement.